This section introduces aspects that may help facilitate a better understanding of the disclosure. Accordingly, these statements are to be read in this light and are not to be understood as admissions about what is or is not prior art.
Atmospheric cold plasma (ACP) technology has been getting more importance as a non-thermal processing technique to inactivate pathogenic microbes in food products (Surowsky, et al., Int'l J. Food Microbiol. 174 (2014) 63-71). The technique utilizes an electrical discharge between two electrodes which lead to generation of cold plasma, a source of electrons, ions, UV light, and reactive gas species, which assist inactivating pathogenic microbes and therefore offer a useful sterilization process. Atmospheric cold plasma has been applied to a wide range of food products, including cheese, lettuce, egg shells, blue berries, strawberries, ham, pork loins, and bacon (ibid.), and liquid products, such as milk, juices (Almeida, et al., Innovative Food Science and Emerging Technologies, 32 (2015), 127-135; Kim, et al., Food Control 47(2015) 451-456).
However, recent studies have suggested that practical uses of ACP in liquid foods sterilization is still a challenge. Work conducted on liquid foods like milk, apple juice and orange juice has shown some positive results in killing microbes. Currently there are no reports on processing tender coconut water using high voltage atmospheric cold plasma, even though other techniques like thermal and non-thermal technologies has been reported in literature (N. K. Mahnot et al., LWT-Food Science and Technology, 59(2), 1191-1195 (2014)).
The coconut is an important fruit tree in the tropical regions. The edible parts of the coconut fruit, including coconut meat and coconut water, is the endosperm tissue (Yong, et al., Molecules 2009, 14, 5144-5164). Coconut water is of cytoplasmic origin, which should not be confused with coconut milk obtained from grating the solid endosperm (meat). Even though coconut water is mainly water (ca. 94%), it contains significant and most useful components, such as phytohormones, micronutrients (including inorganic ions and vitamins), sugars, sugar alcohols, lipids, amino acids, organic acids and enzymes (ibid.). Therefore coconut water is widely consumed due to its beneficial properties to health. It is also believe that coconut water could be used as an important alternative for oral rehydration and may offer protection against myocardial infarction. In addition, coconut water is widely used in the plant tissue culture industry (ibid.).
In order to take advantage of the benefits of coconut water, a sterilized, pathogen-free product is most desirable for human and animal consumption. There are still unmet needs on further improvement of the current process to prepare safe liquid food products for human and animal that meet the requirements of the Food and Drug Administration (FDA) achieving a 5-log bacterial reduction (www.fda.gov/Food/GuidanceRegulation/).